Window with anti-bacterial and/or anti-fungal feature and method of making same

ABSTRACT

Certain example embodiments of this invention relate to a window having anti-fungal/anti-bacterial properties and/or self-cleaning properties, and a method of making the same. In certain example embodiments, a silver based layer is be provided and the layer(s) located thereover (e.g., the zirconium oxide inclusive layer) are designed to permit silver particles to migrate/diffuse to the surface over time to kill bacteria/germs at the surface of the coated article thereby creating an anti-bacterial/anti-fungal effect. In certain example embodiments, silver may also or instead be mixed in with other material as the top layer of the anti-bacterial coating.

This application is a divisional of application Ser. No. 12/929,303,filed Jan. 13, 2011 (now U.S. Pat. No. 8,092,912), which is a divisionalof Ser. No. 11/412,118, filed Apr. 27, 2006 (now U.S. Pat. No.7,892,662), the entire disclosures of which are all hereby incorporatedherein by reference in this application.

This invention relates to a window having anti-fungal/anti-bacterialproperties and/or self-cleaning properties, and a method of making thesame.

BACKGROUND OF THE INVENTION

Vehicle windows (e.g., windshields, backlites, sunroofs, and sidelites)are known in the art. For purposes of example, vehicle windshieldstypically include a pair of bent glass substrates laminated together viaa polymer interlayer such as polyvinyl butyral (PVB). It is known thatone of the two glass substrates may have a coating (e.g., low-E coating)thereon for solar control purposes such as reflecting IR and/or UVradiation, so that the vehicle interior can be more comfortable incertain weather conditions. Conventional vehicle windshields are made asfollows. First and second flat glass substrates are provided, one ofthem optionally having a low-E coating sputtered thereon. The pair ofglass substrates are washed and booked together (i.e., stacked on oneanother), and then while booked are heat bent together into the desiredwindshield shape at a high temperature(s) (e.g., 8 minutes at about600-625 degrees C.). The two bent glass substrates are then laminatedtogether via the polymer interlayer to form the vehicle windshield.

Insulating glass (IG) windows are also known in the art. Conventional IGwindow units include at least first and second glass substrates (one ofwhich may have a solar control coating on an interior surface thereof)that are coupled to one another via at least one seal(s) or spacer(s).The resulting space or gap between the glass substrates may or may notbe filled with gas and/or evacuated to a low pressure in differentinstances. However, many IG units are required to be tempered. Thermaltempering of the glass substrates for such IG units typically requiresheating the glass substrates to temperature(s) of at least about 600degrees C. for a sufficient period of time to enable thermal tempering.Monolithic architectural windows for use in homes or building are alsoknown in the art, and may have a single glass substrate. Again,monolithic windows are often thermally tempered for safety purposes,such tempering involving high temperature during heat treatment.

Other types of coated articles also require heat treatment (HT) (e.g.,tempering, heat bending, and/or heat strengthening) in certainapplications. For example and without limitation, glass shower doorwindows, glass table tops, and the like require HT in certain instances.

Germs are becoming of increasing concern across the world, especially inview of the large amount of international travel taking place in today'ssociety. Sicknesses such as “bird flu”, Severe Acute RespiratorySyndrome (SARS), and other types of flu have surfaced around the worldin recent years and have resulted in many deaths. There exists a need inthe art for elements such as windows that are capable of killing germsand/or bacteria, thereby reducing the likelihood of persons becomingsick due to the flu, SARS, bird flu, and the like. It would be highlyadvantageous if such characteristics of a window could be combined withscratch resistant features.

Photocatalytic coatings are also sometimes desirable in windowapplications. Photocatalytic coatings are also known as self-cleaningcoatings, where the coating reacts with and decomposes organic compoundsor pollutants into inorganic non-harmful compounds such as CO₂ and/orH₂O.

Accordingly, in certain example embodiments of this invention, it willbe appreciated that there exists a need in the art for a coated article(e.g., for use in a window or table-top glass) havinganti-fungal/anti-bacterial properties. In certain example embodiments ofthis invention, it may also be desirable for the coated article to haveself-cleaning properties and/or scratch resistance properties. Incertain example non-limiting instances, it would be advantageous toprovide a window that is both scratch resistant and could function tokill certain bacteria and/or fungus which come into contact with thewindow thereby reducing the chances of persons in buildings using suchwindows becoming sick. In certain example instances, it would beadvantageous to provide a window that is both scratch resistant andcould function in a self-cleaning manner in certain example non-limitinginstances. In still further example non-limiting embodiments, it wouldbe desirable to provide a window having both photocatalytic functionsand anti-fungal/anti-bacterial functions. While coatings herein areoften used in the context of windows, they also may be used in thecontext of table-tops or in other applications in certain exampleinstances.

BRIEF SUMMARY OF EXAMPLES OF INVENTION

Certain example embodiments of this invention relate to a window havinganti-fungal/anti-bacterial properties and/or self-cleaning properties,and a method of making the same. In certain example non-limitingembodiments, there is provided a method of making a coated article(e.g., window such as for a vehicle, building, shower door, or the like)that is capable of being heat treated so that after being heat treated(HT) the coated article is scratch resistant to an extent more thanuncoated glass.

In certain example embodiments of this invention, an anti-fungal and/oranti-bacterial silver inclusive layer is provided under one or morelayers. The layer(s) over the silver are specially designed so as to beporous thereby permitting silver particles to migrate or diffusetherethrough to the surface of the window over long periods of time. Theporous layer(s) over the silver may be of or include a metal oxide incertain example embodiments of this invention, such as an oxide oftitanium or zirconium. For example, the porous layer(s) over the silvermay be designed so as to have a stress and/or density that causes somedegree of porosity therein which permits the silver to migrate/diffuseto the surface of the window by way of zig-zagging through grainboundaries defined in the porous layer(s). In other example embodiments,the porous layer(s) over the silver may be designed so as to have tinypinholes and/or nano-holes defined therein which permit the silver tomigrate/diffuse therethrough to the surface of the window over time.Alternatively, the porous layer(s) may permit the silver particles tomigrate to the surface over time through a combination of tiny pinholesand via grain boundaries in the porous layer(s). When the silverparticles reach the surface in a substantially continuous manner overtime, they function to kill at least some bacteria and/or fungus thatmay come into contact with the silver, or proximate the silver, on thesurface of the window.

In certain example embodiments, the silver is protected from theenvironment by the porous layer(s) provided over the silver. It is notedthat the silver layer may be a continuous layer of or based on silver incertain example embodiments, but alternatively may be a non-continuouslayer made up of a plurality of spaced apart silver or silver basedparticles or globs (e.g., colloids) in other example embodiments. One ormore porous layer(s) over the silver may be photocatalytic(self-cleaning) in certain example embodiments of this invention.

In certain example embodiments of this invention, a photocatalytic layer(e.g., of or including crystalline TiO₂ such as the anatase type) isprovided over a zirconium oxide inclusive layer in a window unit. Suchembodiments may or may not be used in combination with the silverinclusive anti-bacterial/anti-fungal feature discussed herein (e.g., thephotocatalytic layer and the zirconium oxide inclusive layer may both beporous and may both be located over the silver inanti-bacterial/anti-fungal embodiments). The use of the zirconium oxidelayer under the photocatalytic layer significantly improves thedurability of the coated article, while permitting the article torealize low contact angle (θ) and self-cleaning which are both desirablein many situations.

Coated articles according to certain example embodiments of thisinvention may be used in the context of shower door windows,architectural windows, vehicle windows, IG window units, picture framewindows, or the like. While coated articles according to this inventionare particularly adapted for use in windows, this invention is not solimited as coated articles according to this invention may also be usedfor table tops or any other suitable application.

Methods of making such coated articles for use in windows or the likeare also provided. In certain example embodiments, a layer of orincluding zirconium nitride and/or zirconium oxide is formed on a glasssubstrate. In certain example instances, the zirconium nitride and/oroxide layer may be doped with other material(s) such as F, C and/or Ce.Optional fluorine (F) and carbon (C) dopants, for example, have beenfound to increase visible transmission of the coated article. While thezirconium nitride and/or oxide is formed on the glass substrate, theremay be other layer (e.g., a silver based layer) therebetween; thus, theword “on” is not limited to directly on herein. Optionally, a carboninclusive layer (e.g., diamond-like carbon (DLC)) may be provided overthe zirconium inclusive layer. This carbon inclusive layer may be usedto generate energy during heat treatment (HT) for transforming at leastanother layer in the coating so as to form a new post-HT layer(s) whichwas not present in the post-HT form before the HT (e.g., the zirconiumnitride may be transformed into zirconium oxide as a result of the HT;and/or the zirconium based layer may have a degree of tensile stresstherein post-HT which was not present in the layer pre-HT). The coatedarticle including the zirconium nitride and/or oxide layer, the silverbased layer (optional), and the carbon inclusive layer (optional) isheat treated for thermal tempering or the like. As a result of the heattreating, the zirconium nitride inclusive layer if used transforms intoa layer comprising zirconium oxide (this post-HT zirconium oxide layermay or may not include nitrogen in different embodiments). The post-HTlayer of or including zirconium oxide is scratch resistant (SR) incertain example embodiments. In certain example instances, the heattreatment also causes a change in stress of the zirconium based layer(e.g., the zirconium based layer may have a degree of tensile stresstherein post-HT which was not present in the layer pre-HT), such stresspermitting crystal grain boundaries and/or tiny pinholes to be presentin the layer to allow optional silver migration therethrough over time.Following the heat treatment, optionally, a photocatalytic layer (e.g.,of or including crystalline TiO₂ such as of the anatase type) can beformed on the glass substrate over the zirconium oxide inclusive layerand over the optional silver based layer. The photocatalytic layer maybe formed using a colloidal solution, and/or a sol-gel, with subsequentcuring, in certain example embodiments of this invention.

In certain example embodiments of this invention, there is providedcoated article including a coating supported by a glass substrate, thecoating comprising: a layer comprising silver on the glass substrate; alayer comprising zirconium oxide (Zr_(x)O_(y)), where y/x is from about1.2 to 2.5, on the glass substrate over at least the layer comprisingsilver; a photocatalytic layer comprising an anatase oxide of titaniumon the glass substrate over at least the layer comprising silver and thelayer comprising zirconium oxide; and wherein each of the layercomprising zirconium oxide and the photocatalytic layer comprising theanatase oxide of titanium are porous so as to permit silver from thelayer comprising silver to migrate and/or diffuse to the outwardmostsurface of the coated article over time.

In other example embodiments of this invention, there is provided acoated article including a coating supported by a glass substrate, thecoating comprising: a layer comprising silver; a layer comprisingzirconium oxide on the glass substrate over at least the layercomprising silver; a photocatalytic layer comprising at least one metaloxide on the glass substrate over at least the layer comprising silverand the layer comprising zirconium oxide; and wherein each of the layercomprising zirconium oxide and the photocatalytic layer comprising themetal oxide are porous so as to permit silver from the layer comprisingsilver to migrate and/or diffuse to the outwardmost surface of thecoated article over time.

In still further example embodiments of this invention, there isprovided a anti-bacterial window including an anti-bacterial coatingsupported by a glass substrate, the coating comprising: a layercomprising silver; at least one layer comprising a metal oxide on theglass substrate over at least the layer comprising silver; and whereinall layer(s) on the glass substrate over the layer comprising silver areporous so as to permit silver from the layer comprising silver tomigrate and/or diffuse to the outwardmost surface of the coating overtime, said outermost surface of the coating also being a major surfaceof the window.

In other example embodiments of this invention, there is provided amethod of making an anti-bacterial coated article, the methodcomprising: providing a glass substrate; forming a layer comprisingsilver on the glass substrate; forming a porous layer comprising a metaloxide on the glass substrate over at least the layer comprising silver,so that the porous layer comprising the metal oxide is sufficient porousso as to cause silver from the layer comprising silver to migrate and/ordiffuse outwardly to the surface of the coated article over time.

In still further example embodiments of this invention, there isprovided a method of making a coated article, the method comprising:providing a glass substrate; depositing in wet form on the glasssubstrate a colloidal dispersion including each of metal oxide colloidsand silver colloids; and curing the colloidal dispersion so as to forman anti-bacterial and/or anti-fungal layer comprising each of the metaloxide and silver as an outermost layer of a coating on the glasssubstrate.

In certain example embodiments of this invention, the silver (Ag) may bereplaced by or supplemented by copper (Cu).

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram illustrating a method of making ananti-bacterial/anti-fungal coated article according to an exampleembodiment of this invention, before and after optional heat treatment.

FIG. 2 is a schematic diagram illustrating a method of making aphotocatalytic coated article according to another embodiment of thisinvention, before and after heat treatment.

FIG. 3 is a cross sectional view of a coated article made according tothe FIG. 1 embodiment, the view schematically showing how silverparticles migrate or diffuse to the surface of the article over time foran anti-bacterial/anti-fungal effect.

FIG. 4 is a cross sectional view of a coated article according to anexample of this invention, illustrating silver ions stored betweenlayers of zirconia.

FIG. 5 is a top view illustrating how stress evolves for the FIG. 4article after heat treatment, to provide micro-channels perpendicular tothe plane of the film.

DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS OF THE INVENTION

Referring now more particularly to the accompanying drawings in whichlike reference numerals indicate like parts or layers throughout theseveral views.

Certain example embodiments of this invention relate to a window havinganti-fungal/anti-bacterial properties and/or self-cleaning properties,and a method of making the same. Coated articles according to certainexample embodiments of this invention may be used in the context ofshower door windows, architectural windows, vehicle windows, IG windowunits, picture frame windows, or the like. While coated articlesaccording to this invention are particularly adapted for use in windows,this invention is not so limited, as coated articles according to thisinvention may also be used for table tops or any other suitableapplication. The coated article may be heat treated in certaininstances. In certain example embodiments of this invention, there isprovided a method of making a coated article (e.g., window such as for avehicle, building, shower door, or the like) that is capable of beingheat treated so that after being heat treated (HT) the coated article isscratch resistant to an extent more than uncoated glass.

FIG. 1 is a schematic diagram illustrating a method of making ananti-bacterial/anti-fungal coated article for use in a window or thelike according to an example embodiment of this invention, before andafter optional heat treatment; and FIG. 3 is a cross sectional view of acoated article made according to the FIG. 1 embodiment. The FIG. 1, 3embodiment may or may not include the photocatalytic top layer indifferent alternatives of this invention. Meanwhile, the FIG. 2embodiment does not have the silver based layer and instead is aschematic diagram illustrating a method of making a photocatalyticcoated article according to another embodiment of this invention, beforeand after heat treatment. Before getting into much detail, a generaldescription of the various embodiments will be made with respect toFIGS. 1-3.

In certain example embodiments of this invention, referring to FIGS. 1and 3, an anti-fungal and/or anti-bacterial silver inclusive layer 6 isprovided on a glass substrate 1 under one or more layers (e.g., one ormore of layers 7, 9, 11 and/or 12). In the final product, the layers 11and 12 (or just layer 11 if layer 12 is not used) over the silver 6 arespecially designed so as to be porous thereby permitting silverparticles originating from the silver based layer 6 to migrate ordiffuse therethrough to the surface 15 of the window over long periodsof time. The porous layer(s) 11, 12 over the silver 6 may be of orinclude a metal oxide in certain example embodiments of this invention,such as an oxide of titanium or zirconium.

For example, the porous layer(s) 11, 12 over the silver 6 may bedesigned so as to have a stress and/or density that causes some degreeof porosity therein which permits silver based particles from the silverlayer 6 to migrate/diffuse to the surface 15 of the window by way ofzig-zagging through grain boundaries defined in the porous layer(s) 11,12 (e.g., see FIG. 3). In certain example embodiments, the porouslayer(s) 11 and/or 12 over the silver 6 may be designed so as to havetiny pinholes and/or nano-holes defined therein which permit the silverparticles originating from layer 6 to migrate/diffuse therethrough tothe surface 15 of the window over time (e.g., see FIG. 3).Alternatively, the porous layer(s) 11 and/or 12 may permit the silverparticles from the silver based layer 6 to migrate to the surface 15over time through a combination of tiny pinholes and via grainboundaries in the porous layer(s) (e.g., see FIG. 3). When the silverparticles from the silver layer 6 reach the surface 15 in asubstantially continuous manner over time, they function to kill atleast some bacteria and/or fungus that may come into contact with thesilver, or proximate the silver, on the surface 15 of the window.

It is noted that the amount or degree of silver migration/diffusion maybe controlled by environmental factors such as humidity and/ortemperature. For instances, little or no migration may occur at very lowtemperatures and/or in low humidity conditions. However, increasedsilver migration/diffusion to the surface 15 may occur when the windowis exposed to high humidity and/or high temperature conditions. Thus, itwill be appreciated that the silver migration/diffusion does not have tobe constant, either with respect to degree of existence.

In certain example embodiments, the silver based layer 6 where thesilver based particles originate is protected from the environment bythe porous layer(s) 1 and/or 12 provided over the silver based layer 6.It is noted that the silver layer 6 may be a continuous layer of orbased on silver in certain example embodiments, but alternatively may bea non-continuous layer made up of a plurality of spaced apart silver orsilver based particles or globs (e.g., colloids) in other exampleembodiments.

Referring to FIGS. 1-3, one or more porous layer(s) 12 over the silver 6may be photocatalytic (self-cleaning) in certain example embodiments ofthis invention. In certain example embodiments of this invention, aphotocatalytic layer 12 (e.g., of or including crystalline TiO₂ such asof the anatase type) is provided over a zirconium oxide inclusive layer11 in a window unit. Such embodiments may or may not be used incombination with the silver 6 inclusive anti-bacterial/anti-fungalfeature discussed herein (e.g., the photocatalytic layer 12 and thezirconium oxide inclusive layer 11 may both be porous and may both belocated over the silver 6 in anti-bacterial/anti-fungal embodiments, butneed not be porous in embodiments where the silver 6 is not used such asin the FIG. 2 embodiment). The use of the zirconium oxide layer 11 underthe photocatalytic layer 12 significantly improves the durability of thecoated article, while permitting the article to realize low contactangle (θ) and self-cleaning which are both desirable in many situations.

Methods of making such coated articles for use in windows or the likeare also provided. In certain example embodiments, a layer 7 of orincluding zirconium nitride and/or zirconium oxide is formed on a glasssubstrate 1. In certain example instances, the zirconium nitride and/oroxide layer 7 may be doped with other material(s) such as F, C and/orCe. Optional fluorine (F) and carbon (C) dopants, for example, have beenfound to increase visible transmission of the coated article followingHT. While the zirconium nitride and/or oxide layer 7 is formed on theglass substrate, there may be other layer(s) (e.g., a silver based layer6 and/or a dielectric film 3) therebetween; thus, the word “on” is notlimited to directly on herein. Optionally, a carbon inclusive layer(e.g., diamond-like carbon (DLC)) 9 may be provided over the zirconiuminclusive layer 7. This carbon inclusive layer 9 may be used to generateenergy during heat treatment (HT) for transforming at least anotherlayer (e.g., 7) in the coating so as to form a new post-HT layer(s)(e.g., 11) which was not present in the post-HT form before the HT(e.g., the zirconium nitride may be transformed into zirconium oxide asa result of the HT; and/or the zirconium based layer may have a degreeof tensile stress therein post-HT which was not present in the layerpre-HT). The coated article including the zirconium nitride and/or oxidelayer 7, the silver based layer (optional) 6, and the carbon inclusivelayer (optional) 9 is heat treated for thermal tempering or the like. Asa result of the heat treating, the zirconium nitride inclusive layer 7if used transforms into a layer comprising zirconium oxide 11. Thispost-HT zirconium oxide based layer 11 may or may not include nitrogenin different embodiments of this invention. The post-HT layer of orincluding zirconium oxide 11 is scratch resistant (SR) in certainexample embodiments.

In certain instances, the heat treatment (HT) may involve heating thesupporting glass substrate, with the layers thereon, to temperature(s)of from 550 to 800 degrees C., more preferably from 580 to 800 degreesC. (which is well above the burn-off temperature of DLC). Certainexample embodiments of this invention relate to a technique for allowingthe post-HT coated article to be more scratch resistant than uncoatedglass.

In certain example instances, the zirconium based layer 7 may beinitially formed in a manner which causes the heat treatment to cause achange in stress of the zirconium based layer from pre-HT layer 7 topost-HT layer 11. For instance, the zirconium nitride based layer 7prior to HT may have compressive stress, or substantially no stress, andfollowing HT the post-HT zirconium oxide inclusive layer 11 may have asa result of the HT a degree of tensile stress which permits or causescrystal grain boundaries and/or tiny pinholes or nanoholes to be presentin the layer 11 to allow silver migration therethrough over time.Following the heat treatment, optionally, a photocatalytic layer (e.g.,of or including crystalline TiO₂ such as of the anatase type) 12 may beformed on the glass substrate 1 over the zirconium oxide inclusive layer11 and over the optional silver based layer 6. The photocatalytic layer12 may be formed using a colloidal solution, and/or a sol-gel, withsubsequent curing, in certain example embodiments of this invention.

FIG. 4 is a cross sectional view of a coated article according to anexample of this invention, illustrating silver ions of layer 6 storedbetween layers 3 and 11 of zirconia (zirconium oxide). Meanwhile, FIG. 5is a top view illustrating how stress evolves for the FIG. 4 articleafter heat treatment, to provide micro-channels or nanoholesperpendicular to the plane of the film. As explained above, thesemicro-channels or nanoholes in at least layer 11 allow silver migrationtherethrough over time toward the upper surface of the coated article.

Now, a more detailed discussed will be made as to certain exampleembodiments of this invention and as to how such embodiments may bemade.

Turning first to the FIG. 1, 3 embodiment of this invention, an exampledescription is provided as to how this embodiment may be made in certainexample instances.

FIG. 1 is a schematic diagram illustrating how a coated article can bemade according to an example embodiment of this invention. Initially, acoated article is formed using a glass substrate 1 as a support. Thecoated article includes, supported by glass substrate 1, at least oneoptional dielectric barrier film 3, a layer of or including silver 6provided for anti-fungal and/or anti-bacterial purposes, a layer of orincluding zirconium nitride 7 (e.g., ZrN, or any other suitablestoichiometry), and an optional top layer of or including carbon such asDLC 9. Glass substrate 1 is typically of or includes soda-lime-silicaglass, although other types of glass may be used in certain instances.

Dielectric barrier film 3 includes one or more layers and is provided inorder to prevent sodium diffusion from the glass substrate 1 into thesilver 6 during and/or after HT (i.e., a diffusion barrier). Dielectricbarrier film 3 may comprise a layer(s) of or including zirconium oxide,zirconium nitride, zirconium oxynitride, zinc oxide, silicon nitride,silicon oxynitride, silicon oxide, or the like. Barrier film 3 may havecompressive stress both before and after HT in certain exampleembodiments of this invention, since compressive stress may help thefilm to block sodium migration from the glass substrate. Barrierlayer(s) 3 is formed on the glass substrate 1 via sputtering, or via anyother suitable technique. Dielectric barrier film 3 is from about50-1,000 Å thick, more preferably from about 80-500 Å thick, in certainexample embodiments of this invention.

Silver based layer 6 is provided on the glass substrate 1 over at leastthe optional barrier film 3 in certain example embodiments. However, itis possible for the silver based layer 6 to be formed directly on theglass substrate 1 when dielectric barrier film 3 is not used. Silverlayer 6 may be from about 20-400 Å thick, more preferably from about20-200 Å thick, and even more preferably from about 20-100 Å thick, incertain example embodiments, of this invention. Because the coatedarticle is used in window applications or the like, the silver layer 6is thin enough so as to be substantially transparent in certain exampleembodiments, but thick enough so as to provide sufficient silver foranti-bacterial and/or anti-fungal purposes. Moreover, the silver basedlayer 6 may also function as an infrared (IR) blocking layer in certainexample embodiments of this invention, thereby permitting the window toblock additional IR radiation from entering a building or the like. Thesilver layer 6 may be continuous or discontinuous in differentembodiments of this invention.

Still referring to the product in FIG. 1 prior to HT, zirconium nitrideand/or zirconium oxide inclusive dielectric layer 7 may be provided onthe glass substrate 1 between silver based layer 6 and carbon inclusivelayer 9 in certain example embodiments of this invention, as shown inFIG. 1. In certain example embodiments, zirconium nitride inclusivelayer 7 may be located directly between layers 6 and 9; however in otherexample embodiments other layer(s) (not shown) may be provided betweenthe zirconium nitride inclusive layer 7 and one or both of layers 6, 9.The zirconium nitride inclusive layer 7 may consist essentially of (a)zirconium and nitride, (b) zirconium and oxygen, or (c) zirconium,oxygen and nitrogen in different example embodiments of this invention.However, the zirconium inclusive dielectric layer 7 may also includeother materials including but not limited to dopants such as Al, F, Ce,C or the like in certain example embodiments of this invention.Zirconium inclusive dielectric layer 7 may be formed by sputtering orthe like in certain example embodiments of this invention.

The pre-HT layer 7 may include from about 10-70% Zr, more preferablyfrom about 30-65% Zr, even more preferably from about 40-60% Zr, andmost preferably from about 45-55% Zr in terms of atomic %; and fromabout 20-60% N, more preferably from about 30-50% N in terms of atomic%, in certain example embodiments of this invention. In certain exampleembodiments of this invention, zirconium nitride inclusive layer 7 mayhave a density of at least 6 gm/cm³, more preferably at least 7 gm/cm³.Additionally, in certain example embodiments, zirconium nitrideinclusive layer 7 may have an average hardness of at least 650 kgf/mm,more preferably of at least 700 kgf/mm, and/or may have a bond overlappopulation of at least 0.25 (more preferably at least about 0.30) forstrength purposes. In certain example instances, many of the Zr—N bondsin layer 7 may be of the covalent type, which are stronger than ionicbonds, for strength purposes. It is also noted that in certain exampleembodiments of this invention, the ZrN of layer 7 may have a meltingpoint of at least 2,500 degrees C., and it may be about 2,980 degrees C.in certain example instances. In certain example embodiments of thisinvention, the zirconium nitride of layer 7 may be represented byZr_(x)N_(y), where the ratio x:y is from 0.8 to 1.2, and is preferablyabout 1.0 in certain example embodiments. Zirconium inclusive layer 7may have compressive stress as originally formed on the glass substrateprior to HT. These same zirconium nitride characteristics that areexplained above with respect to layer 7 also apply to layer 3 when thelayer 3 is formed of zirconium nitride and/or oxide.

The optional layer 9 comprising DLC may be of any suitable type of DLC,including but not limited to any of the DLC types described in any ofU.S. Pat. Nos. 6,592,993; 6,592,992; 6,531,182; 6,461,731; 6,447,891;6,303,226; 6,303,225; 6,261,693; 6,338,901; 6,312,808; 6,280,834;6,284,377; 6,335,086; 5,858,477; 5,635,245; 5,888,593; 5,135,808;5,900,342; and/or 5,470,661, all of which are hereby incorporated hereinby reference. For purposes of example only, DLC inclusive layer 9 may befrom about 5 to 1,000 angstroms (Å) thick in certain example embodimentsof this invention, more preferably from 10-300 Å thick, and mostpreferably from 45 to 65 Å thick. In certain example embodiments of thisinvention, DLC layer 9 may have an average hardness of at least about 10GPa, more preferably at least about 20 GPa, and most preferably fromabout 20-90 GPa. Such hardness renders layer 9 resistant to scratching,certain solvents, and/or the like. Layer 9 may, in certain exampleembodiments, be of or include a special type of DLC known as highlytetrahedral amorphous carbon (t-aC), and may be hydrogenated (t-aC:H) incertain embodiments. In certain hydrogenated embodiments, the t-aC:Htype of DLC 9 may include from 4 to 39% hydrogen, more preferably from5-30% H, and most preferably from 10-20% H. This t-aC or t-aC:H type ofDLC for layer 9 may include more sp³ carbon-carbon (C—C) bonds than sp²carbon-carbon (C—C) bonds. In certain example embodiments, at leastabout 50% of the carbon-carbon bonds in DLC layer 9 may be sp³ typecarbon-carbon (C—C) bonds, more preferably at least about 60% of thecarbon-carbon bonds in the layer 9 may be sp³ carbon-carbon (C—C) bonds,and most preferably at least about 70% of the carbon-carbon bonds in thelayer 9 may be sp³ carbon-carbon (C—C) bonds. In certain exampleembodiments of this invention, the DLC in layer 9 may have an averagedensity of at least about 2.4 gm/cm³, more preferably at least about 2.7gm/cm³.

The DLC based layer 9 may be formed in any suitable manner, such asusing an ion beam(s) from at least one ion source. Example linear ionbeam sources that may be used to deposit DLC inclusive layer 9 onsubstrate 1 include any of those in any of U.S. Pat. Nos. 6,261,693,6,002,208, 6,335,086, or 6,303,225 (all incorporated herein byreference). When using an ion beam source to deposit layer 9,hydrocarbon feedstock gas(es) (e.g., C₂H₂), HMDSO, or any other suitablegas, may be used in the ion beam source(s) in order to cause the sourceto emit an ion beam toward substrate 1 for forming layer 9. It is notedthat the hardness and/or density of layer 9 may be adjusted by varyingthe ion energy of the depositing apparatus. In certain exampleembodiments, at least about 2,000 V (anode to cathode volts), e.g.,about 3,000 V, may be used in the ion source in depositing layer 9. Itis noted that the phrase “on the substrate” as used herein is notlimited to being in direct contact with the substrate as other layer(s)may still be provided therebetween.

For purposes of example only, certain example thicknesses for the pre-HTlayers shown at the top of FIG. 1 are set forth below, with the layersbeing listed in order from the glass substrate outwardly.

Example Coating (Top of FIG. 1) Layer Thicknesses (Pre-HT)

Layer General More Preferred Most Preferred Dielectric (film 3) 50-1,000Å   80-500 Å 120-250 Å  Silver (layer 6) 20-400 Å 20-200 Å 20-100 Å ZrN(layer 7) 40-500 Å 50-400 Å 90-220 Å DLC (layer 9) 5-1,000 Å  10-300 Å 40-65 Å

Once the pre-HT coated article shown at the top of FIG. 1 is formed, itmay be subjected to heat treatment sufficient for at least one of heatbending, thermal tempering, and/or heat strengthening. Referring to FIG.1, when subjected to HT (e.g., in a furnace using temperature(s) of from550 to 800 degrees C., more preferably from 580 to 800 degrees C.), theupper or outer DLC inclusive layer 9 if provided burns off due tocombustion because of the high temperatures used during HT. Inparticular, at least DLC layer 9 (which may be hydrogenated) may act asa fuel which upon combustion with oxygen from the atmosphere during HTproduces carbon dioxide and water. This exothermic reaction, caused bycombustion of hydrogenated carbon from at least DLC layer 9, may causespontaneous propagation of a combustion wave through the initialreactants. The high temperature developed during this combustion heatsthe layer 7 comprising zirconium nitride and/or oxide to atemperature(s) well above the heat treating temperature used by thefurnace. For example, the combustion of the DLC 9 and/or from the HT mayheat part of all of the layer 7 comprising zirconium nitride and/oroxide to a temperature of at least about 1200 degrees C., morepreferably at least about 1500 degrees C., and most preferably at leastabout 2,000 degrees C.

Because the layer 7 comprising zirconium nitride and/or oxide is heatedto such a high temperature due to the DLC combustion during HT, at leasta substantial portion of the zirconium nitride therein is transformedduring the HT into a new post-HT layer of or including zirconium oxide11. In other words, the HT causes at least a substantial portion of thenitride to transform into an oxide. The new post-HT layer comprisingzirconium oxide 11, shown in the middle and bottom portions of FIG. 1,may also include nitrogen (and/or other dopants) in certain exampleembodiments of this invention (e.g., ZrO:N; ZrO₂:N; or any othersuitable stoichiometry). The new post-HT layer comprising zirconiumoxide 11 (optionally with nitrogen) is surprisingly scratch resistantthereby providing a heat treated scratch resistant coated article. It isnoted that the phrase “zirconium oxide” as used herein includes ZrO₂and/or any other stoichiometry where Zr is at least partially oxided.

The post-HT layer comprising zirconium oxide 11 may include from 0-30%nitrogen in certain example embodiments of this invention, morepreferably from 0-20% nitrogen, even more preferably from 0-10%nitrogen, and most preferably from about 1-5% nitrogen in certainexample embodiments of this invention. The post-HT layer comprisingzirconium oxide 11 may include from about 10-70% Zr, more preferablyfrom about 20-60% Zr, even more preferably from about 30-55% Zr, andmost preferably from about 30-45% Zr in terms of atomic %. Moreover, thepost-HT layer(s) comprising zirconium oxide 11 in certain exampleembodiments of this invention may include from about 10-85% oxygen, morepreferably from about 30-80% oxygen, even more preferably from about40-70% oxygen, and most preferably from about 50 to 70% oxygen.

In certain example embodiments of this invention, the post-HT layercomprising zirconium oxide 11 includes a nanocrystalline cubic latticestructure (although the pre-HT layer comprising zirconium nitride didnot in certain instances). As explained above, zirconium nitridetypically does not grow in cubic phase unless at a temperature of atleast about 2,000 degrees C. It has surprisingly been found that thecombustion generated during the HT may cause at least part of the pre-HTlayer comprising zirconium nitride 7 to be heated sufficiently to causeit to grow in the cubic phase and become a post-HT layer 11 comprising ananocrystalline cubic lattice structure including zirconium oxide (withor without nitrogen) which is very scratch resistant in certain exampleembodiments of this invention. It has surprisingly been found that theuse of zirconium nitride (e.g., ZrN) in the pre-HT layer 7 is especiallybeneficial with respect to allowing a post-HT phase-transformed layer 11including Zr to be formed which is very scratch resistant.

Following the heat treatment, the silver layer 6 is still present asshown in the middle and bottom portions of FIG. 1. However, the HT maycause the silver from layer 6 to begin to migrate or diffuse outwardlyaway from the glass substrate toward the surface 15 of the coatedarticle (e.g., through layer(s) 11 and/or 12). Prior to the heattreatment, the zirconium inclusive layer 7 may have compressive stressand/or substantially no stress. However, the layer 7 may be designed soas to realize tensile stress after the HT. In certain exampleembodiments of this invention, the zirconium nitride and/or oxideinclusive layer 7 may be transformed by the HT process into a layer 11of or including zirconium oxide which has a degree of tensile stresstherein which was not present in the layer pre-HT. The tensile stress inlayer 11 is advantageous in that it permits the layer 11 to be porousthereby allowing silver particles from the silver layer 6 to diffuseand/or migrate outwardly toward the surface 15 over time. In certaininstances, the tensile stress can permits or cause crystal grainboundaries and/or tiny pinholes or nanoholes to be present in the layer11 to allow silver migration therethrough toward the surface 15 of thecoated article over time. Note that when optional photocatalytic layer12 is not used, the surface 15 of the coated article is the top of thezirconium oxide based layer 11 (i.e., the final product may be as shownin the middle of FIG. 1 in certain instances). An example way in whichto cause the post-HT layer comprising zirconium oxide 11 to have enoughtensile stress to permit silver migration/diffusion is to dope theoriginally formed zirconium nitride and/or oxide layer 7 with Ce or thelike. As explained above, the silver reaching the surface 15 of thecoated article is advantageous in that it helps kill bacteria and/orgerms on the surface of the coated article, thereby functioning as ananti-bacterial/anti-fungal agent.

In the FIG. 1, 3 embodiment, photocatalytic layer 12 is optional.However, the photocatalytic layer 12 may be applied on the glasssubstrate 1 over the zirconium oxide inclusive layer 11 in certainexample embodiments of this invention as shown in FIGS. 1 and 3. When HTis used, the application of the photocatalytic layer 12 is typicallyperformed following the HT as shown in FIG. 1. The photocatalytic layer12 may be of any suitable photocatalytic material in differentembodiments of this invention, but titanium oxide (e.g., TiO₂) ispreferred in certain instances. The layer 12 is of or includes aphotocatalytically active composition containing a photocatalyticallyactive oxide of a transition metal (MO) or (MO₂) such as TiO₂ catalystfor producing a substantially transparent self-cleaning coating. Thelayer 12 will thus react with and decompose organic compounds orpollutants, deposited thereon from the environment, under the effects ofexposure to sunlight such as UV. The organic pollutants are decomposedto simple inorganic compounds such as CO₂ and/or H₂O, and/or variousmineral acids, which may re-enter the atmosphere and/or wash off due torain, wind or the like, so that the coated article is self-cleaning withan efficiency that is dependent on the degree of photocatalytic activityin the catalyst, which may be proportional to the total surface area ofthe photocatalytic material particles to which the pollutants areexposed. For example and without limitation, when anatase TiO₂ isilluminated by ultraviolet (UV) radiation with a wavelength below about390 nm, electrons in the valence band are excited to the conduction bandleaving behind positive-charged holes which are reactive with absorbedwater vapor hydroxide ions, resulting in the formation ofpositive-charged hydroxyl radicals, (OH)⁺. The hydroxyl radicals inphotocatalytic layer 12 are strong oxidizing radicals which can reactwith and strip pollutants to produce simpler, non-offensive productssuch as CO₂ and/or H₂O, or HCl is halogen pollutants are involved. It isnoted that the photocatalytic layer 12 may include other material(s)such as an acrylic urethane polymer which may be used to improvewettability properties and/or reduce any potential yellow color due tolayer 12.

Photocatalytic layer 12 may be formed on the glass substrate in anysuitable manner. For example, the photocatalytic layer 12 may bedeposited on the glass substrate 1 over layers 3, 6 and/or 11 using aspray technique, a spin coating technique, a flow coating technique, orthe like. The photocatalytic layer 12 may be initially deposited in awet form including colloids (e.g., titania colloids) in solution. Forexample and without limitation, the photocatalytic layer 12 mayinitially deposited as an application of a colloidal of anatase (e.g.,from 0.1 to 2%, more preferably from 0.2 to 1.2% anatase TiO₂ insolution such as water or the like). The colloidal of anatase may bedoped with Zn cations or the like in certain example instances. Anataseis a special crystalline form of titanium oxide which is photocatalytic.This colloidal may be deposited following the application of anunderlying primer in certain instances. The primer (not shown) may besilica based in certain example embodiments of this invention, and maybe deposited in any suitable manner including but not limited to spray,meniscus flow, or flame combustion. In certain example embodiments, anacidic catalyzed silica may be provided in the dispersion along with thetitania colloids, or in a primer, in order to produce good wettability.An example acidic catalyzed silica is glycidoxypropyl trimethoxysilane.For example and without limitation, the photocatalytic layer 12 may beformed in any manner described in, and may be of any material describedin, any of U.S. Pat. Nos. 6,884,752, 2005/0234178, 6,107,241, and/or6,939,611, 6,235,401, the disclosures of which are all herebyincorporated herein by reference.

Heat may then be used to cure the colloidal layer, with the heat eitherbeing generated from a heat treatment oven, radiant heaters, or from aheat treatment performed just prior to application of the colloidaldispersion. Example heat treatments for curing the photocatalytic layerso as to remove the solution therefrom, leaving the titania to formphotocatalytic layer 12, may be from about 200-600 degrees C., morepreferably from about 400-550 degrees C., with an example being forabout 3 minutes at about 500 degrees C. The time and temperature of thecuring as well as the original size of the particles in the colloidaldetermines the scratch resistance of the layer 12. When the heat used inthe curing causes the solution and/or solvent to evaporate or burn offthereby leaving the metal oxide (e.g., TiO₂) making up photocatalyticlayer 12, the resulting photocatalytic layer 12 is porous in nature.This is because the metal oxide (e.g., TiO₂) molecules making upphotocatalytic layer 12 are not very tightly packed together (the layeris not particularly dense) due to the previous presence of the solutionor solvent which had taken up space between the metal oxide (e.g., TiO₂)molecules. The amount of nano-porosity in layer 12 can be used to (a)substantially match the refractive index (n) of the photocatalytic layer12 to that of the zirconium inclusive layer 11, (b) improve thephotocatalytic behavior of the layer 12, and/or (c) create nano-pores,pinholes and/or crystal grain boundaries which can be used as diffusionand/or migration paths for the silver particles from silver layer 6 tomigrate toward the surface 15 of the coated article foranti-fungal/anti-bacterial purposes.

When TiO₂ is formed by sputter-deposition, it typically is very dense(is not porous), is not anatase, and has a refractive index (n) of atleast 1.4. This would be undesirable because such a sputter-depositedTiO₂ layer would not be photocatalytic, would not substantially matchthe refractive index of underlying zirconium oxide based layer 11, andwould not be porous to permit migration or diffusion of the silver tothe surface 15 over time. However, when the TiO₂ is formed using a wetdeposition of a colloidal dispersion or sol including titania, and isthen heat treated to remove the liquid, the resulting layer 12 based onTiO₂ is highly desirable in that (a) it comprises anatase TiO₂ so thatit is photocatalytic, (b) it is not very dense (due to the areapreviously occupied by the liquid) so that the refractive index is muchless, and (c) due to its not very dense nature, it is porous andincludes migration/diffusion paths for the silver to makes its way tothe surface 15 of the coated article over time to cause ananti-bacterial/anti-fungal effect. Thus, in effect, silver from thesilver layer can be substantially continuously pumped to the surface ofthe coated article over time so that silver can be provided at thesurface of the coated article for long periods of time (e.g., months oreven years in certain typical environmental conditions).

In certain example embodiments of this invention, the anatase titaniumoxide (e.g., TiO₂) based photocatalytic layer 12 has a refractive index(n) of from about 1.75 to 2.15, more preferably from about 1.85 to 2.15,and most preferably from about 1.9 to 2.1, so as to substantially matchthe refractive index of the underlying zirconium oxide inclusive layer11. In certain example embodiments of this invention, the zirconiumoxide inclusive layer 11 has a refractive index (n) of from about 1.95to 2.15, more preferably from about 2.0 to 2.1, with an example beingabout 2.05. In certain example embodiments the index of refraction oflayer 12 does not differ from that of layer 11 by more than 0.1, morepreferably by not more than about 0.05. Thus, it will be appreciatedthat the refractive indices (n) of the layers 11 and 12 can besurprisingly matched in the final product in certain example embodimentsof this invention, even though they are of different materials typicallyhaving much different refractive indices. This matching of refractiveindices of layers 11 and 12 is advantageous in that it permits a moredesirable color of the final product to be achieved, and lessreflectance to be achieved.

Another advantage of a TiO₂ photocatalytic layer 12 formed in the mannerdescribed above is that it can be made to have a very low contact anglethereby being hydrophilic. In certain example embodiments of thisinvention, the coated article with such a layer 12 can have a contactangle θ of no more than about 12 degrees, more preferably no more thanabout 10 degrees, and possibly no more than about 7 or 5 degrees. Thisis advantageous in that it allows fog or water to more easily shed offof the window in certain example embodiments of this invention.

In certain window and/or table-top embodiments of this invention, thecoated article shown in FIG. 1, 3 has a visible transmission of at leastabout 50%, more preferably at least about 60%, and possibly at leastabout 70%. Such high visible transmissions are desirable for windowapplications.

For purposes of example only certain example thicknesses for the post-HTcoated article shown at the bottom of FIG. 1 are set forth below, withthe layers being listed in order from the glass substrate outwardly.

Example Coating (FIG. 1) Layer Thicknesses (Post-HT)

Layer General More Preferred Most Preferred Dielectric (layer 3)50-1,000 Å   80-500 Å 120-250 Å Silver (layer 6) 20-400 Å 20-200 Å 20-100 Å ZrO:N (layer 11) 50-800 Å 70-600 Å 100-350 Å TiO₂ (layer 12)100-900 Å  300-600 Å  350-450 Å

It can be seen from the above that post-HT Zr inclusive layer 11 istypically thicker than is pre-HT Zr inclusive layer 7. In other words,the thickness of the Zr inclusive layer may increase during HT. Incertain example embodiments of this invention, the thickness of the Zrinclusive layer (e.g., from layer 7 to layer 11) may increase at leastabout 5% during or due to HT, more preferably at least about 10%, andmost preferably at least about 40%. This increase in thickness is causedby the transformation of layer 7 into layer 11, where oxygen migratesinto the post-HT layer 11 (i.e., more oxygen migrates into the post-HTlayer 11 than nitrogen leaves in terms of atomic % and/or size incertain instances).

In certain example embodiments of this invention, the heat treated layer11 comprising zirconium oxide includes Zr_(x)O_(y), wherein y/x is fromabout 1.2 to 2.5, more preferably from about 1.4 to 2.1. Moreover, it ispossible that residual carbon can remains in the zirconium oxide layer11 following HT due to the presence of the pre-HT DLC layer 9. Incertain example embodiments of this invention where DLC 9 was presentprior to HT, the zirconium oxide layer 11 includes from 0.25 to 20% C,more preferably from 0.25 to 10% C, and most preferably from 0.25 to 5%C.

It has been found that doping zirconium nitride and/or oxide 7 with Fand/or C prior to heat treatment tends to increase the visibletransmission of the heat treated coated article. Doping with F and Cresults in a film with lower absorption compared to undoped films.Moreover, it has been found that the addition of F and/or C to theselayers does not significantly change the optics of the coated article,or the biaxial film stress of the films prior to HT. Furthermore, when Fand/or C are provided in layer 7, both scratch resistance andenvironmental stability (e.g., measured via salt fog test) of the HTproduct are substantially unaffected by the presence of F and/or C. Ofcourse, following heat treatment the layer comprising zirconium oxide 11may also be doped with F and/or C in a corresponding manner since it waspresent before HT. This doping of zirconium nitride (and/or zirconiumoxide) with F and/or C may be used in conjunction with any embodimentdiscussed herein. In certain example embodiments of this invention, oneor more of layers 7, 11 may be doped with from about 0.01 to 10.0% F,more preferably from about 0.1 to 8.0% F, even more preferably fromabout 0.3 to 5.0% F, still more preferably from about 0.4 to 2% F, andmost preferably from about 0.5 to 1.0% F (in terms of atomic percent).Moreover, in certain example embodiments of this invention, one or moreof layers 7, 11 may be doped with from about 0.01 to 10.0% C, morepreferably from about 0.1 to 8.0% C, even more preferably from about 0.3to 5.0% C, still more preferably from about 0.4 to 2% C, and mostpreferably from about 0.5 to 1.0% C (in terms of atomic percent). Thedoping with F and C may be used together so that one or more of layers7, 11 is/are doped with both F and C in these amounts. Alternatively,only one of the dopants F and C may be used for a layer. Thus, in suchalternative embodiments, one or more of layers 7, 11 may be doped with Fin the aforesaid amount(s), but not doped with C. As yet anotheralternative, one or more of layers 7, 11 may be doped with C in theaforesaid amount(s), but not doped with F.

Another notable aspect of certain example embodiments of this inventionis the extreme increase in visible transmission caused by heattreatment. In certain example embodiments, visible transmissionincreases by at least about 20 visible transmission % due to HT, morepreferably at least 30%, and most preferably at least 40%. For example,in certain examples of this invention that have been made, the pre-HTvisible transmission has been about 36-37%. Following heat treatment forabout 400 seconds at about 640 degrees C., the post-HT visibletransmission was about 77-81%. In each case, the visible transmissionincreased by about 40-45% due to HT. For purposes of example andunderstanding, if a pre-HT coated article had a visible transmission of36% and following HT the post-HT coated article had a visibletransmission of 80%, then the visible transmission increased 44% (i.e.,80%−36%=44%) due to HT. The apparent reason for this significantincrease in visible transmission due to HT is the vanishing of at leastsome DLC due to HT because of the aforesaid combustion thereof. DLCblocks visible transmission to some extent, and its combustion anddisappearance during HT allows visible transmission of the resulting HTcoated article to significantly increase as shown above. Thus, not onlydoes the DLC combustion act as a fuel which allows transformation of theZr inclusive layer, but it also allows visible transmission tosignificantly increase

An alternative embodiment of this invention, with reference to FIGS. 1and 3, is to deposit silver (Ag) simultaneously with the TiO₂. In otherwords, the photocatalytic layer 12 would include both TiO₂ and Ag insuch embodiments. Such an embodiment may or may not be used incombination with the provision of silver layer 6. In other words, thesilver layer 6 may be eliminated if this approach is taken in certaininstances, or it need not be eliminated if this approach is taken. Forexample, a simultaneous (along with the TiO₂) application of a colloidalsilver can be performed in such a way that the photocatalytic layer 12would also have an anti-bacterial/anti-fungal property as deposited,without the need for the diffusion/migration of the silver although thismay still be possible. The silver particles deposited along with layer12 can be chosen so as to have a size permitting them to fit between theTiO₂ particles in the photocatalytic layer 12 so as to also mechanicallystrengthen the coating into a metal-ceramic composite. In certainexample embodiments of this invention, the layer 12 may include fromabout 50-99% TiO₂ (or some other photocatalytic or other suitable metaloxide) and from about 1-30% Ag. In certain such embodiments, the layer12 may include from about 1-20% silver, more preferably from about 1-10%silver.

FIG. 2 is a schematic diagram illustrating a method of making aphotocatalytic coated article according to another embodiment of thisinvention, before and after heat treatment. In particular, the FIG. 2embodiment illustrates silver layer 6 and/or dielectric film 3 may beeliminated from the FIG. 1 embodiment. The FIG. 2 embodiment is the sameas the FIG. 1 embodiment described above, except that dielectric film 3and/or silver layer 6 are eliminated in the FIG. 2 embodiment. It isnoted that the aforesaid options and characteristics (e.g., using acombination of silver and titanium oxide, layer thicknesses, how layersare deposited/formed, characteristics of layers, etc.) described withrespect to the FIG. 1 embodiment as to elements 1, 7, 9, 11 and 12 arealso applicable to the FIG. 2 embodiment because these layers are alsopresent in the FIG. 2 embodiment.

For any embodiment herein, it is noted that the silver may be replacedwith copper (Cu). For instance, copper may be used instead of silver foranti-bacterial and/or anti-fungal effects. In still further exampleembodiments of this invention, a mixture or combination of silver andcopper may be used instead of only silver.

Any suitable type of glass substrate 1 may be used in differentembodiments of this invention. For example, various types of soda limesilica glass or borosilicate glass may be used for substrate 1. However,in certain example embodiments of this invention, the coating of any ofthe aforesaid embodiments may be supported by a special type of glasssubstrate that has a very high visible transmission and a very clearcolor. In particular, in such certain example embodiments of thisinvention, the glass substrate 1 may be any of the glasses described incommonly owned U.S. patent application Ser. No. 10/667,975, thedisclosure of which is hereby incorporated herein by reference. Incertain preferred embodiments, the resulting glass has visibletransmission of at least 85%, more preferably at least 88%, and mostpreferably at least 90% (e.g., at a reference thickness of about 0.219inches or 5.56 mm). The advantage of using such a glass substrate 1 isthat the resulting HT product is caused to have a visual appearancesimilar to that of uncoated clear glass—even though the coating isprovided thereon. In addition to the base glass, examples of the glassbatch and/or final glass are set forth below (in terms of weightpercentage of the total glass composition, unless otherwise listed asppm):

Example Colorants and Oxidizer Cerium in Glass Substrate

Ingredient General Preferred More Preferred Best total iron (Fe₂O₃):0.01-0.20% 0.01-0.15% 0.02-0.12% 0.03 to 0.10% cobalt oxide: 0 to 15 ppm0.1 to 10 ppm 0.5 to 5 ppm 0.5 to 3 ppm cerium oxide:   0-1.0%0.01-1.0%  0.01-0.5%  0.05 to 0.2%  erbium oxide: 0 to 1.0% 0.01-0.30%0.02-0.20% 0.02 to 0.15% titanium oxide: 0 to 0.5% 0 to 0.2% 0.001 to0.05% 0.01 to 0.02% chromium oxide: 0 to 10 ppm  0 to 8 ppm   0 to 5 ppm  1 to 5 ppm glass redox: <=0.20 <=0.12 <=0.10 <=0.08 % FeO:0.0001-0.05%  0.0001-0.01%  0.001-0.008% 0.001-0.003%

It is noted that in other embodiments of this invention, additionallayers (not shown) may be added to the coated articles discussed above,and/or certain layer(s) may be deleted.

While the invention has been described in connection with what ispresently considered to be the most practical and preferred embodiments,it is to be understood that the invention is not to be limited to thedisclosed embodiments, but on the contrary, is intended to cover variousmodifications and equivalent arrangements included within the spirit andscope of the appended claims.

1. A method of making an anti-bacterial coated article, the methodcomprising: providing a glass substrate; forming a layer comprisingsilver on the glass substrate; forming a porous layer comprising a metaloxide on the glass substrate over at least the layer comprising silver,so that the porous layer comprising the metal oxide is sufficient porousso as to cause silver from the layer comprising silver to migrate and/ordiffuse outwardly to the surface of the coated article over time.
 2. Themethod of claim 1, further comprising forming a layer comprisingzirconium nitride on the glass substrate over at least the layercomprising silver, and then heat treating the glass substrate with thelayer comprising zirconium nitride thereon in a manner so that followingthe heat treating the layer comprising zirconium nitride has transformedinto a porous layer comprising zirconium oxide which is said porouslayer comprising the metal oxide.
 3. The method of claim 1, furthercomprising forming a porous photocatalytic layer on the glass substrateover at least the porous layer comprising the metal oxide.
 4. A methodof making a coated article, the method comprising: providing a glasssubstrate; depositing in wet form on the glass substrate a colloidaldispersion including each of metal oxide colloids and silver colloids;and curing the colloidal dispersion so as to form an anti-bacterialand/or anti-fungal layer comprising each of the metal oxide and silveras an outermost layer of a coating on the glass substrate.
 5. The methodof claim 4, wherein a layer comprising zirconium oxide is providedbetween the glass substrate and the anti-bacterial and/or anti-fungallayer, and wherein the metal oxide is an oxide of titanium.